On June 25, 2026, the Supreme Court, in Monsanto Co. v. Durnell, ruled on the question of whether the Federal Insecticide, Fungicide, and Rodenticide Act ("FIFRA") preempts state-law failure-to-warn claims against Monsanto for its Roundup products. Monsanto Co. v. Durnell, 2026 U.S. LEXIS 2721 (June 25, 2026). In a 7-2 opinion the Court dispatched Missouri resident John Durnell, who alleged that Monsanto failed to warn him of Roundup's cancer risks, and that he developed non-Hodgkin's lymphoma as a result. Id. at *6-7. As a former landscaper who is all too familiar with Roundup products, I found this opinion particularly interesting. This opinion is expected to block thousands of failure to warn suits,[1] but will also provide greater regulatory ease for industry players. Lindsay Whitehurst, Supreme Court ruling blocks thousands of lawsuits against maker of Roundup Weedkiller, PBS Newshour, June 25, 2026; Bayer Global, Monsanto wins landmark Roundup™ case at U.S. Supreme Court, June 25, 2026. Additionally, this decision will serve to weaken the United States tort system's role as a decentralized back-end regulatory body.
The Court found appellant Monsanto's argument convincing. Monsanto's main point was that Mr. Durnell's state tort claim would require Monsanto to add a cancer warning to Roundup's label, despite federal law requiring Monsanto to use the Environmental Protection Agency-approved label that does not contain a cancer warning. Monsanto at *6-7. The court entered a discussion of the history of FIFRA and the EPA's role in registering pesticides, which concluded with discussion of a provision of FIFRA titled "Uniformity." Id. at *7-13. This provision, "prohibits States from imposing 'any requirements for labeling or packaging in addition to or different from those required under' FIFRA." Id. at *12-13 (citing 7 U.S.C. § 136v).
The classification of glyphosate was central to this discussion. Id. at *13-14. Glyphosate is a widely used herbicide that has been registered as a pesticide in the United States since 1974. United States Environmental Protection Agency, Glyphosate (last updated May, 5, 2026). Glyphosate is also a central ingredient in Roundup. Monsanto at *13. Ever since glyphosate's registration with the EPA, the EPA has repeatedly re-evaluated glyphosate, and has continued to conclude that "glyphosate is not likely to cause cancer." Id. Despite the International Agency for Research on Cancer classifying glyphosate as a probable carcinogen, the EPA has still adhered to its longstanding position that glyphosate is not carcinogenic. Id. at *13-14. The Court pointed out that the EPA's position on glyphosate is shared by regulators in Canada, Australia, Japan, and the European Union. Id. at *14. Thus, because the EPA still views glyphosate as unlikely to cause cancer, the "EPA has not required glyphosate-based pesticides like Roundup to include a cancer warning on their labels." Id. Further, the Court held consistent with the FIFRA "Uniformity" provision that "Monsanto legally must use a label without a cancer warning unless and until the EPA approves or requires a change." Id. This in turn expressly preempts Durnell's state failure-to-warn claim, because such would require Monsanto to add a cancer warning to its labels which would be "in addition to" and "different from" Monsanto's obligations under FIFRA. Id. at *21-22.
Justice Jackson, joined by Justice Gorsuch, offered a view consistent with the lower courts in her dissent. In her view, Durnell's failure-to-warn claim is not different from FIFRA's requirements, but is equivalent to FIFRA's misbranding prohibition. Monsanto, 2026 U.S. LEXIS 2721, at *36 (Jackson, J., dissenting). Justice Jackson continued by explaining that FIFRA's preemption provision requires that when FIFRA itself or the EPA's regulations necessitate specific statements on a pesticide label that a state law requiring additional or different statements is preempted. Id. at *41. However, Justice Jackson stated that in the absence of such requirements, "a state-law duty that parallels FIFRA's misbranding prohibition is not preempted." Id. In her view, Durnell's claim has the same practical effect as FIFRA's misbranding prohibition, as, "both require a pesticide manufacturer to adequately warn users of the potential dangers of using its product." Id. at *43 (citing Durnell v. Monsanto Co., 707 S. W. 3d 828, 833 (Mo. Ct. App. 2025)). As such, Durnell's claim does not impose a labeling requirement, "in addition to or different from" FIFRA's requirements. Id. at *43. Then turning to FIFRA's statutory text, Justice Jackson made the point that the EPA's approval of a label cannot set out a requirement under Section 136v(b) because the statute itself states that EPA's approval of a pesticide's label cannot conclusively establish that the pesticide is not misbranded. Id. at *45-47. Further, FIFRA's misbranding provision continues to apply to pesticides, even once they have already been registered. Id. at *47.
After rejecting the majority's express preemption argument, Justice Jackson turned to Monsanto's contention that Durnell's failure-to-warn claim was impliedly preempted. Id. at *57. Monsanto argued that it is impossible to comply with the labeling requirements of both FIFRA and Missouri law simultaneously. Id. Justice Jackson pointed out that stopping the sale of Roundup entirely is a possible solution, and that both state and federal law require Monsanto to stop selling Roundup if the label does not have an adequate warning. Id. Justice Jackson also mentioned that Monsanto overstated the difficulty of adding a cancer warning. Id. at *58. Specifically, she mentioned that EPA regulations permit pesticide manufacturers to make minor modifications, and that the EPA had allowed manufacturers to add state-specific cancer warnings as minor modifications on at least six occasions without agency approval, including a subsidiary of Monsanto's parent company Bayer. Id. at *59-60. Justice Jackson ended her dissent by lamenting the fact that the majority's decision, "unjustifiably closes the courthouse doors to state tort plaintiffs like Durnell." Id. at *61.
The tort system in the United States plays a much bigger role in regulation than in many countries. As Justice Jackson emphasized in her dissent, "[p]arallel state tort liability is an enforcement tool that can have salutary information-forcing effect, and that, in turn, helps ensure the effectiveness of FIFRA's misbranding prohibition." Monsanto, 2026 U.S. LEXIS 2721, at *43-44 (Jackson, J., dissenting). Although the EPA's classification of glyphosate is consistent with many other countries (id. at *14), this is not a guarantee of its safety. There are many times in the history of this country that the courts have been at the forefront of pesticide regulation and spurred regulatory change, even when the EPA takes the opposite position.
One such pertinent example is litigation regarding the EPA's treatment of the pesticide chlorpyrifos. In League of United Latin American Citizens v. Regan, the Ninth Circuit ordered the EPA to either modify chlorpyrifos food tolerances and publish a finding that those tolerances were safe, or to revoke chlorpyrifos food tolerances all together. 996 F.3d 673, 678 (9th Cir. 2021). This order came after the EPA refused to act on a 2007 petition from environmental groups that asked the EPA to prohibit foods that contain residue from chlorpyrifos. Id. at 677. The Court concluded that the EPA lacked the power to deny the 2007 petition, and that the EPA's decision to do so was arbitrary and capricious under the Administrative Procedure Act. Id. at 700.
League of United Latin American Citizens did not involve state tort claims like in Monsanto, but the case does illustrate the concerns of whether the EPA can be trusted to act in the best interest of the American people when regulating pesticides. The EPA, after all, is a heavily politicized executive agency that shifts priorities every four to eight years with the change of Administrations. State failure-to-warn claims prior to Monsanto served as an additional regulatory check and provided Mr. Durnell with compensation for his non-Hodgkin's lymphoma. Monsanto, 2026 U.S. LEXIS 2721, at *14-15. While this decision creates greater regulatory consistency for producers of glyphosate-based products, it ultimately removes the ability of my fellow former landscapers like Mr. Durnell to receive compensation for heightened exposure to a significant health risk of which they were never put on notice. By eliminating state failure-to-warn claims in the context of EPA approved pesticide labels, the Supreme Court simultaneously removes both a unanimously decided jury verdict, and an important form of back-end tort-based regulation.
